The present invention relates generally to power supplies for portable phones, and is particularly concerned with a portable phone with internal and external battery, and a power supply control system and method for the portable phone.
Portable phones may have an internal battery for providing power, or an external battery which is releasably mounted on the phone body while in use, and is removed for re-charging when the phone is not in use. Batteries typically require changing after a large number of discharge and charge cycles, typically after 500 to 1000 cycles. When the battery is internal, the user must have access to the internal battery without disassembling the phone. This can involve a relatively complex procedure.
As internal components decrease in size, an internal battery dominates the overall length, width, and thickness of a portable phone. An external battery attached to the phone also involves extra plastic thickness in the overall phone assembly. Another problem with either internal or external batteries is potential loss of calls if the battery loses power during a call. In a conventional portable phone, it is not possible to change or re-charge the battery without turning off the phone.